This is more common than you might think. Back when I worked on a COBOL compiler at IBM one of our test cases was an "expert system" that turned ~20 lines of bu

This is more common than you might think. Back when I worked on a COBOL compiler at IBM one of our test cases was an "expert system" that turned ~20 lines of business-specific DSL into ~100k lines of COBOL. It was extremely un-fun to deal with.